Recommended Posts

Yeast not only gives rise to bread, it gave rise to an answer to a question that has eluded evolutionary biologists.

"To understand why the world is full of plants and animals, including humans, we need to know how one-celled organisms made the switch to living as a group, as multicelled organisms," said Sam Scheiner, program director in the National Science Foundation (NSF)'s Division of Environmental Biology. "This study is the first to experimentally observe that transition, providing a look at an event that took place hundreds of millions of years ago."

Share this post

Link to post

Share on other sites

Notice how they view the significance of their findings, in terms of altruism and sacrifice for the common good:

"A cluster alone isn't multiellular," Ratcliff said. "But when cells in a cluster cooperate, make sacrifices for the common good, and adapt to change, that's an evolutionary transition to multicellularity."

In order for multicellular organisms to form, most cells need to sacrifice their ability to reproduce, an altruistic action that favors the whole but not the individual, Ratcliff said. For example, all cells in the human body are essentially a support system that allows sperm and eggs to pass DNA along to the next generation. Thus, multicellularity is by its nature extremely cooperative. "Some of the best competitors in nature are those that engage in cooperation, and our experiment bears that out," said Travisano.

Share this post

Link to post

Share on other sites

Ha! Obviously someone doesn't buy into the "Selfish Gene" way of looking at it. Under this paradigm it's what is in the "interest" of the genes, not the cells, nor even the organism or entire freaking species, that counts. The genes don't care if only some cells can propagate them so long as they get propagated.

Share this post

Link to post

Share on other sites

Bringing in the "altruism" twist is almost ubuquitous in biology right now. At least it seems like it as an outsider. Every single time I read about some new finding with cells or biomatter there's always some bone thrown to "altruism". What a joke.

"We are trying to understand the chemical origins of life. One of the interesting questions is where carbohydrates come from because they are the building blocks of DNA and RNA. What we have achieved is the first step on that pathway to show how simple sugars -- threose and erythrose -- originated. We generated these sugars from a very simple set of materials that most scientists believe were around at the time that life began."

Researchers led by Professor Lee Cronin at the University of Glasgow have developed inorganic chemical cells (iCHELLs), which show redox activity, chirality, as well as selective permeability towards small molecules, and which can be nested within one another, potentially allowing stepwise reactions to occur in sequence within the cell.

After reading Harriman's "The Logical Leap", I have to wonder just how many pieces of this puzzle are already discovered out there to assemble?

Link to post

Share on other sites

"I study molecular complementarity mainly because I'm a pattern seeker, even when I was an undergraduate," Root-Bernstein said. "I hope to help answer how life evolved to take advantage of molecular complementarity so that the two concepts are virtually synonymous."

Share this post

Link to post

Share on other sites

"Miller's classic "primordial soup" experiment, published in Science in 1953, is still widely used today in high school chemistry labs to mimic chemical reactions that occur in vapor-rich volcanic eruptions. The experiment circulated methane, ammonia, water vapor and hydrogen in a closed experiment, simulating the earth's early atmosphere and sent a lightning-like spark through it. Over a series of days, organic compounds formed in the mixture, demonstrating how Earth's primitive atmosphere may have given rise to life."

Share this post

Link to post

Share on other sites

Although other scientists recently announced the creation of a "synthetic cell," only its genome was artificial. The rest was a hijacked bacterial cell. Fully artificial life will require the union of both an information-carrying genome and a three-dimensional structure to house it.

"In this paper the Yarus group has made the amazing discovery that even an extremely tiny RNA can by itself catalyze a key reaction that would be needed to synthesize proteins," Blumenthal said. "Nobody expected an RNA molecule this small and simple to be able to do such a complicated thing as that."

Share on other sites

In the laboratory, FTT reactions produce amino acids, and can show a preference for making straight-chain molecules. "In almost all of the 14 meteorites we analyzed, we found that most of the amino acids had these straight chains, suggesting FTT reactions could have made them," said Burton.

"We have found an unknown branch of the tree of life that lives in this lake. It is unique! So far we know of no other group of organisms that descend from closer to the roots of the tree of life than this species. It can be used as a telescope into the primordial micro-cosmos," says an enthusiastic associate professor, Kamran Shalchian-Tabrizi, head of the Microbial Evolution Research Group (MERG) at the University of Oslo.

Share this post

Link to post

Share on other sites

While some cyanobacteria were known to form extracellular calcium carbonate within stromatolites, their formation within the cell had never been observed. Another distinctive feature of the new species is that it accumulates strontium and barium and incorporates them into the carbonate.

This finding is significant for the interpretation of the ancient fossil record. If the cyanobacteria associated with stromatolites formed carbonates inside their cells rather than outside, they would not have been preserved in the fossil record.

Share this post

Link to post

Share on other sites

Duax and his team have developed efficient ways to search through the gene banks looking for all copies of the same family of protein. They concentrated their efforts on proteins that are found on the surface of cell components called ribosomes. The ribosomal proteins are among the most accurately identified proteins, and because they are not transferred between individuals independent of reproduction, are good candidates for tracing the evolution of all species.

Share this post

Link to post

Share on other sites

Starting with a mix of chemicals, many of them thought to have been present on the early Earth, Powner has now created a sugar like that in DNA, linked to a molecule called AICA, which is similar to a base. (Journal of the American Chemical Society, doi.org/h6q

Link to post

Share on other sites

The astronomers found molecules of glycolaldehyde -- a simple form of sugar [1] -- in the gas surrounding a young binary star, with similar mass to the Sun, called IRAS 16293-2422. Glycolaldehyde has been seen in interstellar space before [2], but this is the first time it has been found so near to a Sun-like star, at distances comparable to the distance of Uranus from the Sun in the Solar System. This discovery shows that some of the chemical compounds needed for life existed in this system at the time of planet formation [3].

One of the big questions is whether it is common that these organic molecules are formed so early in the star and planet formation process -- and how complex they can become before they are incorporated into new planets.

"knowledge of a species' genes -- and how certain external conditions affect the proteins encoded by those genes -- could be used to determine a predictable evolutionary pattern driven by outside factors."

"The finding of parallel evolution in not two, but numerous herbivorous insects increases the significance of the study because such frequent parallelism is extremely unlikely to have happened simply by chance,"

Edited October 26, 2012 by dream_weaver

Share this post

Link to post

Share on other sites

"The power of what we've done is to survey diverse organisms facing a similar problem and find striking evidence for a limited number of possible solutions," he said. "The fact that many of these solutions are used over and over again by completely unrelated species suggests that the evolutionary path is repeatable and predictable."

A team of scientists from the United States and Sweden announced that they have discovered AEG within cyanobacteria which are believed to be some of the most primitive organisms on Earth. Cyanobacteria sometimes appear as mats or scums on the surface of reservoirs and lakes during hot summer months. Their tolerance for extreme habitats is remarkable, ranging from the hot springs of Yellowstone to the tundra of the Arctic.